Reintroduce scroll-snap-type: x mandatory; on highlights container which was erroneously removed in #14965 (#15111)

Author: abeddow91

dotcom-rendering/src/components/ScrollableHighlights.importable.tsx

@@ -45,6 +45,7 @@ const carouselStyles = css`
 	scroll-behavior: auto;
 	overscroll-behavior-x: contain;
 	overscroll-behavior-y: auto;
+	scroll-snap-type: x mandatory;
 
 	${from.mobileLandscape} {
 		padding: 0 ${horizontalPaddingMobileLandscape}px;